Schecter
et al. report they find comparatively high levels of PBDEs
in breast milk from mothers in Texas. The levels measured are comparable
to those found by other recent US studies in breast
fat and maternal and cord
serum. They are up to 100 times higher than recent measurements
of PBDEs in European breast milk.

While
a definitive answer for the high levels in the US compared to Europe
awaits further systematic study, it most likely relates to differences
in the use of brominated flame retardants in various consumer products,
combined with recent European moves to decrease exposures.

What
did they do? Schecter et al. obtained breast milk
from volunteers at two health centers in Texas (Austin and Dallas).
Samples were then shipped to two World Health Organization-certified
laboratories in Canada and Germany for analysis of PBDE levels.
In all, measurements of 13 different PBDE congeners were obtained
from 47 individuals, few if any of whom were exposed occupationally.

What
did they find? This first-ever study of PBDE levels in
American's breast milk finds extremely elevated levels of PBDEs
compared to European levels.

As
seen in the graph to the right, the 10 women (21% of those
sampled) had PBDE concentrations above 100 ppb, with the highest
milk level at 419 ppb. Fifteen women (32% of sample) had levels
over 50 ppb.

The
scientists found no relationship between PBDE levels and the
age of the woman measured, nor did they observe any racial
differences in PBDE concentrations.

As
shown in the graph to the left, the
Texas measurements made by Schecter et al. were dramatically
higher than those reported in recent studies from Europe,
and somewhat higher than recent data from Canada. Levels in
Canada appear to have risen over the past decade.

Graphs
adapted from Schecter et al.

What
does it mean? This study of 47 Texas women adds to the
growing body of scientific evidence demonstrating high levels of
PBDEs in Americans at levels 10 to 100 times that seen in Europe.
It is the first study undertaken of PBDEs in breast milk in the
US.

The
sources of exposure responsible for these high PBDE body burdens
are uncertain. PBDEs are widely used
in a variety of consumer products and can be found in food, household
dust and sewage sludge, among many places. Swedish levels appear
to be declining following implentation of a ban. Coincidentally,
the week that Schecter et al.'s study appeared online (8 August
2003), California's
Governor signed a law banning some PBDEs in California.

The
main concern about PBDEs is their ability to disrupt thryoid function,
and thus interfere with proper brain development, at least as indicated
by experiments with laboratory animals and cells in culture. No
published epidemiological studies have examined the impact of PBDEs
on people. Yet over the same time period that PBDE body burdens
have been increasing dramatically Americans, we have also witnessed
apparent increases in the frequency of a number of neurobehavioral
abnormalities in people, including autism and attention deficit
hyperactivity disorder. Surely this coincidence warrants investigation.